2 * Generic cpu hotunplug interrupt migration code copied from the
3 * arch/arm implementation
5 * Copyright (C) Russell King
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #include <linux/interrupt.h>
12 #include <linux/ratelimit.h>
13 #include <linux/irq.h>
15 #include "internals.h"
17 static bool migrate_one_irq(struct irq_desc *desc)
19 struct irq_data *d = irq_desc_get_irq_data(desc);
20 struct irq_chip *chip = irq_data_get_irq_chip(d);
21 const struct cpumask *affinity = d->common->affinity;
22 bool brokeaff = false;
26 * IRQ chip might be already torn down, but the irq descriptor is
27 * still in the radix tree. Also if the chip has no affinity setter,
28 * nothing can be done here.
30 if (!chip || !chip->irq_set_affinity) {
31 pr_debug("IRQ %u: Unable to migrate away\n", d->irq);
36 * No move required, if:
37 * - Interrupt is per cpu
38 * - Interrupt is not started
39 * - Affinity mask does not include this CPU.
41 * Note: Do not check desc->action as this might be a chained
44 if (irqd_is_per_cpu(d) || !irqd_is_started(d) ||
45 !cpumask_test_cpu(smp_processor_id(), affinity))
48 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
49 affinity = cpu_online_mask;
53 err = irq_do_set_affinity(d, affinity, false);
55 pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n",
63 * irq_migrate_all_off_this_cpu - Migrate irqs away from offline cpu
65 * The current CPU has been marked offline. Migrate IRQs off this CPU.
66 * If the affinity settings do not allow other CPUs, force them onto any
69 * Note: we must iterate over all IRQs, whether they have an attached
70 * action structure or not, as we need to get chained interrupts too.
72 void irq_migrate_all_off_this_cpu(void)
74 struct irq_desc *desc;
77 for_each_active_irq(irq) {
80 desc = irq_to_desc(irq);
81 raw_spin_lock(&desc->lock);
82 affinity_broken = migrate_one_irq(desc);
83 raw_spin_unlock(&desc->lock);
85 if (affinity_broken) {
86 pr_warn_ratelimited("IRQ %u: no longer affine to CPU%u\n",
87 irq, smp_processor_id());